Roller bit



July 7, 1936. v c. E. REED ROLLER BIT ATTORNEY.

teted .luly

Clarence IE. ed, Wichita, Mans assignor to Chicago Pneumatic Tool iilompany, New ilorlr, hi. it... a corporation off New Jersey Application December a, i933, sci-an. in. minus 29 Claims.

This invention relates to earth boring apparatus and more particularly to drill bits employing roller cutters. An object of the invention is the provision of a roller bit adapted to penetrate 5 rapidly in relatively soft formations, but suitable also for hard formations. The cutter means employed in the present invention comprise a roller cutter preferably of cylindrical form positioned approximately centrally or adjacent the axis of 10 the drill and opposite an unobstructed space following in the path of the central cutter. The

formation at the center of the hole comes into contact with this cutter only and does not engage any other cutter or spindle support which might l5 drag alongthe bottom of the hole and thus retard penetration.

Another object is to provide a novel supporting means for the cutters, which comprises two or more independently mounted roller cutter 20 units. The roller cutter units are arranged to be removable conveniently as well as independently, without sacrificing strength or durability of the parts of the bit. Each cutter spindle is preferably integral with its supporting shank, whereby 25 to assure adequate support for one end of the spindle and to permit the spindle to be large in diameter as compared with the diameter of the bit head.

A further object of this invention is to provide means for discharging flushing fluid against the cutters and against the bottom of the hole. The invention comprises a centrally positioned renewable outlet pipe disposed at the upper end of an inverted ii-shaped recess at the bottom of the bit head, the pipe having a series of discharge openings extending in a plane transverse to the wall of the recess, which plane is common to the res of the cutters. The pipe or conduit is shaped to'provide the minimum friction with the water 40 or other flushing fluid so as to reduce wear and thereby prolong the life of the conduit.

Other objects and features of the present invention will appear more clearly from the following -:description taken in connection with the accompanying drawing and appended claims.

In the drawing Fig. 1 is a sectional view of the lower end of a drill bit embodying the present invention, the section being taken in the plane of the cutter axes;

Fig. 2 is a bottom view of the flushing fluid conduit or wash pipe; and

Fig. 3 is another view of the wash pipe looking in the directions of the arrows in Fig. 2, the lower half of the pipe being shown in full lines and the upper half in a section taken along the line 373.

The invention comprises a bit head it having at its lower end an inverted \l-shaped recess l i, the walls of which flare downwardly and outwardly. A bore l2 centrally located in the bit head communicates with the recess Ill for a purpose here- 5 inaiter described. The walls of the recess ii are cut away to provide seat recesses it on opposite sides of the axis of the bit. These seat recesses communicate with longitudinal bores it. The seat recesses it and bores it are adapted to reeeive and support the upper ends of roller cutter carriers it and ill respectively. Each carrier member comprises a shank it received within bore it and a base is seated within seat recess it. Suitable means (not shown) are provided for holding the shank securely in place on the bit head. The method of securing the roller cutter unit to the bit head is similar to the arrangement shown in applicants prior Patent Re. 17,741, dated July 22, 1930, reierence to which is made for a more complete disclosure of elements not fully illustrated in the drawing of this application.

The base it is provided with a depending por tion 20 from which a spindle 21! projects downwardly and inwardly towards the axis of the .drill. The spindle and. the base are preferably integral to insure adequate-strength. An annular groove 22 surrounding the spindle ti is formed in the base iii. A bushing 23 fits snugly around the spindle ti and has, at one end, a flange 2d seated in the annular groove 22. The engagement between the flange t t and the base plate it is eilective to resist thrusts exerted upon the bushing during the operation of the drill. This flange it also acts as a thrust shoulder for the roller cutter it loosely mounted on the bushing it. The cutter it is preferably of cylindrical shape and of such length that one end thereof is in the same plane as the free enr of the bushing and spindle.

In order to secure the cutter against removal from the bushing, the spindle ii is provided with a threaded bore to receive the bolt or shaft 2% which is provided with a cap 30 engaging the free end of the spindle, bushing and cutter. The cap 30 cooperates with the thrust shoulder it to hold the cutter it against any axial or wabbling movement.

The carrier member l'l is similar in principle but difierent in proportions from the carrier member for the roller cutter unit previously described. It carries a spindle 3! adapted to support a bushing 32 andshaft 33 arranged similarly to the corresponding elements mounted on shaft 2!. Spindle BI is longer than spindle 2i and has a greater included angle with respect to the axis of the bit. A plurality of roller cutters 34 and 35, separated by a spacing washer 36, are mount ed on the bushing 32. These cutters are arranged to rotate on the bushing independently of each other. The base I9 of the carrier member I! is cut away at 38 to permit the cutter 35 to extend further outwardly from the center of the hole.

The roller cutters are arranged to cut the entire area at the bottom of the hole within a circle extending slightly beyond the periphery of the bit head iii. In the embodiment of the invention illustrated in the drawing each cutter operatesover a different annular area and none of the cutters track each other. The central cutter 34 is so positioned that its inner end is close to the axis of the drill (indicated in broken lines in Fig. 1). On the opposite side of the axis and separated from the central cutter by an open space 40 is the side cutter 26 which traverses the outermost annular area or zone at the bottom of the hole. The formation underlying the space 40 is cut by the central cutter 34 and intermediate cutter 35. It will be apparent that more than two cutters could be employed for this purpose if desired.

Preferably, the two spindles 2I and 3| are arranged with their axes in the same plane with each other and with the axis of the bit. This arrangement, however, is not essential, since the spindles may be disposed, for example, in planes 120 degrees apart and there may be more than two spindles.

The cutter units comprising the carrier members I6 and I! are supported in the bit head independently of each other and either one may be removed and replaced as a unit without disturbing the other.

The invention also comprises novel means for distributing flushing fluid to the bottom of the hole and to the cutters. A renewable conduit or wash pipe 4|, shaped to flt the lower end of the bit head I 0 is provided with a cylindrical portion 42 received by the bore I2. The extreme lower end of bore I2 is shaped to flt the conduit 4|. The pipe is held in place by suitable means such as a press flt. The lower end of the pipe or conduit is provided with flaring portions 43 and 44 which terminate inan integral flange or head 46. Head 46 is provided with a plurality of outlets including outlets 48, 49 and 50 arranged in the plane of the spindles 2i and 3| which plane is transverse to the walls of the V-shaped recess II. These openings are separated by baflies BI and 52 of acute angular shape whereby to divert the stream of water or other flushing fluid without materially reducing its velocity or causing undue wear on the pipe. The directions of the outlets 48, 49 and 50 are such that the water impinges directly against the top of each roller cutter. Other outlets 53 and 54, formed in the flaring portions 43 and 44 respectively, provide streams of water tangential to the side cutter 28, a portion of the water striking the cutter and the rest impinging directly against the bottom are contributing factors which enable the bit to penetrate rapidly and to remove the earth formation from the hole as fast as it is drilled. Other advantages resulting from the invention include strength and durability of the parts and convenience in replacing the cutter units when they become worn.

The arrangement for .discharging flushing fluid, which includes the renewable conduit H, is claimed in a divisional application, Serial No. 77,902, filed May 5, 1936.

While the invention has been herein disclosed in what is now considered to be a preferred form, it is to be understood that the invention is not limited to the specific details thereof but covers all changes, modifications and adaptations within the scope of the appended claims.

What I claim is:

1. In earth boring apparatus, a rotatable bit head, a carrier depending from the lower end thereof, and a spindle supported by said carrier at one end and extending therefrom inwardly towards the axis of the bit head, the spindle being of cylindrical shape and having its free end substantially in line with said axis.

2. In earth boring apparatus, a rotatable bit head, a carrier depending from the lower end thereof, a spindle supported. by said carrier at one end and extending therefrom inwardly towards the axis of the bit head, the spindle being of cylindrical shape and having its free end substantially in line with said axis, and a roller cutter of cylindrical shape mounted on said spindle adjacent the free end thereof.

3. An earth boring roller bit comprising a bit head, an independently rotatable roller cutter arranged at the lower face of the bit head intermediate roller cutters that enlarge the hole dug by said first-mentioned cutter, the enlarging cutters being set at different angles to the bit axis on opposite sides of the bit, the first-mentioned cutter being in non-tracking relationship to any other cutter, said cutters cutting the entire area at the bottom of the hole, all cutters being cylindrical in shape and having substantially the same diameter, one of the cutters having means for connecting it to or' detaching it from the bit head without affecting the position of another of said cutters.

4. In an-earth boring drill, the combination of a one-piece drill head having a recess at its lower end, roller cutters in said recess adapted to cut the entire area at the bottom of the hole, a plurality of spindles on which said cutters are rotatably mounted, said spindles converging downwardly and inwardly from the walls of the recess, each of such spindles together with its roller cutter means mounted thereon adapted to be handled as a unit and as such inserted into place with the cutter means within such recess and the spindles within the head, and means for detachably holding said unit to the head, each of said spindles being disposed at a different angle with respect to the vertical axis of the drill, one of the spindles with its holding means being separate from another spindle and holding means therefor.

5. In an earth boring drill, the combination according to the preceding claim in which the cutter means on one spindle is arranged to cut a zone surrounding the zone cut by the cutter means of another spindle.

6. In an earth boring drill, the combination according to claim 4'in which the cutter means On one of the spindles comprises a cylindrical cutter in non-tracking relationship adjacent the vertical axis ofthe drill.

7. A roller boring drill comprising a\ bit head, a carrier member supported thereby, a spindle supported at one end by said carrier member and having a free end adjacent the axis of the drill, a roller cutter mounted upon said spindle, and means for retaining said cutter in place, said retaining means comprising a shaft within said spindle, and having a flange adjacent the free end of the spindle, said flange being of larger diameter than the spindle to prevent removal of the cutter when the flange and shaft are in operative position.

8. A roller bit comprising a bit head, a plurality of roller cutters of cylindrical shape, spindles on which said cutters are mounted, and carrier members for supporting said spindles, said carrier members being detachably connected to the bit head independently of each other.

9. A drill bit according to claim 8 in which the roller cutters are arranged to cut the entire area at the bottom of the hole.

10. A roller drill comprising a bit head, a plurality of roller cutters of cylindrical shape supported on the bottom of the bit head, said cutters being spaced at different distances from the axis of the drill, spindles for mounting the cutters thereon, and a plurality of carrier members for supporting the spindles, said carrier members being independently supported in the bit head.

11. An earth boring drill comprising a bit head, a plurality of roller cutters carried thereby at the lower end of the bit head, and including a central cutter of cylindrical shape disposed adjacent the bit axis and at one side thereof, said cutters being supported by spindles, means for attaching the spindles to the bit head at the outer ends of the spindles, the inner ends of the latter being disconnected from each other whereby to leave an open space adjacent the central cutter.

12. In a roller bit, a bit head having a recess at its lower end, a cutter supporting spindle disposed in said recess and converging downwardly and inwardly towards the axis of the drill, the spindle being supported at its outer end and its inner end being free, and a roller cutter of cylindrical shape mounted upon said spindle, said cutter being so arranged to cut an annular area adjacent the axis of the drill.

13. In earth boring apparatus, a bit head, a carrier member supported therein and having a base portion, a spindle connected, at one end only, to said base portion, and a bushing slipped over the free end of the spindle, one end of the bushing terminating in an annular flange received within an annular groove in said base, the other end being in the plane of the free end of the spindle.

14. In earth boring apparatus, a bit head, a carrier member supported therein and having a base portion, a spindle connected, at one end only, to said base portion, a bushing slipped over the free end of the spindle, one end or the bushing terminating in an annular flange received within an annular groove in said base, the other end being in the plane of the free end of the spindle, one or more roller cutters mounted on said bushing, .said cutter or cutters being confined between said flange and a. retainer member, said retainer.member being telescoped into the free endot the spindle.

15. A roller boring drill comprising a bit head, a plurality of roller cutter units supported thereby, each 'unit comprising a spindle having roller cutter means mounted thereon and having means for attachment to the bit head, said roller cutter means, spindle and attaching means being adapted to be handled together as a unit and as such connected to the bit head in operative position, each spindle with its attaching means being separate from any other spindle and attaching means therefor, each of said cutter means being positioned in non-tracking relationship with any other cutter means.

16. A roller boring drill according to claim 15 in which the axes of all of the spindles are in the same vertical plane as the axis of the bit head.

1'7. A roller boring drill according to claim 15 in which the axes of two of the spindles are inclined at different angles with respect to the bit head axis.

18. An earth boring roller bit comprising a bit head, an independently rotatable roller cutter of cylindrical shape arranged at the lower face of the bit head, other roller cutters that enlarge the hole dug by said first-mentioned cutter, the enlarging cutters being set at an acute angle to the bit axis onopposite sides of the bit, the firstnientioned cutter being in non-tracking relationship to any other cutter, said cutters cutting the entire area at the bottom of the hole, one of said cutters having supporting means for attaching it to and detaching it from the bit head, by movement of the cutter and supporting means as a unit in a direction parallel to the bit head axis, without disturbing the position of another of said cutters with respect to the bit head.

19. A roller boring drill comprising a bit head, a plurality of roller cutter units supported thereby, each unit comprising a spindle having roller cutter means mounted thereon and having means for attachment to the bit head, said roller cutter means, spindle and attaching means being adapted to be handled together as a unit and as such connected to the bit head in operative position, each spindle with its attaching means being separate from any other spindle and attaching means therefor, said cutter units being so arranged that the axis of each spindle is at a diderent angle with respect to the bit head axis than the corresponding angle for the spindle in another unit.

20. In an earth boring tool, a bit head, and means for rotatably mounting a cutter on the under side thereof, said means including a spindle and a terminal member, a support connecting the outer end of the spindle to the bit head leaving the inner end of the spindle free for attachment of the terminal member thereto, an annular wear member carried by said cutter mounting means and providing a bearing surface for sustaining loads of a roller cutter, a roller cutter having a bearing surface complementary to the bearing surface of the wear member, said terminal member having a stem secured within a bore of the spindle and having a flange projecting across the end of the wear member, said flange retaining the wear member and cutter in assembled relation.

21. An earth boring tool according to claim 20 p in which the inner end of the wear member is flush with the free end of the spindle, and said flange abuts thereagainst. 4

22. An earth boring tool according to claim 20 in which the wear member is flanged at its outer end and the inner face of said flange sustains end thrusts of the cutter.

23. An earth boring tool according to claim 20 in which the wear member at its outer end engages with a shoulder of the spindle.

24. In an earth boring tool, a bit head, a downwardly and inwardly inclined spindle at the under side thereof, means connecting the outer end of the spindle to the bit head and leaving the inner end .of the spindle free, a side cutter rotatably mounted upon said spindle and cutting an area including clearance for the bit head, and another spindle projecting inwardly toward the bit head axis but having its axis disposed at a different angle to the bit head axis than the angle of the axis of the other spindle with respect to the bit head axis, a support connecting the last-named spindle to the bit head independently of the means connecting the first-named spindle to the bit head, and roller cutter means on the lastnamed spindle cutting a central area of the hole.

25. In an earth boring tool, a bit head, a downwardly and inwardly inclined spindle at the under side thereof, means connecting the outer end of the spindle to the bit head and leaving the inner end of the spindle free, a side cutter rotatably mounted upon said spindle and cutting an area including clearance for the bit head, and another spindle having its inner end adjacent the bit head axis, a pair of cylindrical roller cutters mounted upon the last-named spindle and cutting the area at the center of the hole left uncut by the side cutter, and a support connecting the last-named spindle to the bit head independently of the means connecting the first-named spindle to the bit head, said spindle axis lying in a vertical plane passing through the bit head axis.

26. In an earth boring drill, the combination of a cylindrical toothed roller cutter traversing an annular path adjacent the vertical axis of the drill, a spindle for said cylindrical cutter inclined to the vertical axis of the drill and at a comparatively low angle to a horizontal plane, additional toothed rotary cutter means on said spindle to enlarge the out made by the cutter first mentioned on the bottom of the hole, a sec-'- ond spindle arranged at a steeper angle to said horizontal plane, a roller cutter mounted on said second spindle to enlarge the cut made by the cutting means on the spindle first mentioned, each of the spindles having their ends which are nearest to the vertical axis of the drill free, said cutter on the second spindle cutting an annular path adjacent the side of the hole including clearance for the drill head, and means-connected with the outer ends of the spindles for attaching said spindles to the bit head, there being a free space at the inner ends of the spindles by which the bottom of the hole is exposed for the discharge of the cuttings, andmeans for delivering flushing fluid to the cutter organization.

27. An earth boring drill according to claim 26, in which the roller cutter on said second spindle is of cylindrical form.

28. An earth boring drill according to claim 26 in which the axes of all the cutters are in the same vertical plane passing through the axis of the drill.

29. An earth boring drill according to claim 26 in which each of the cutters is non-tracking in respect to all the other cutters.

CLARENCE E. REED. 

